Diagnostic challenges in the fine-needle aspiration diagnosis of carotid body paragangliomas: Report of two cases

Two cases of carotid body paraganliomas sampled by fine-needle aspiration ( FNA) cytology prior to other medical diagnostic studies are presented In th e first case, the presence of an ipsilateral ulcerative lesion of the nasop harynx along with pronounced atypia of the specimen posed a challenge to th e correct cytologic interpretation, which was initially sidetracked in far or of a metastatic epithelial lesion. In the second case, a tumor mass of u nusually large size and extension which included the pharynx coupled with a large amount of profusely hemorrhagic aspirate, presented a diagnostic pro blem, which was overcome by processing part of the specimen as a cell block , which by its histologic and immunochemical features provided a definitive pathologic diagnosis. In handling these two clinically complex cases of carotid paraganglioma, tw o learning principles became clear on how to reach a correct FNA diagnosis in such lesions: 1) The anatomic location of the lateral neck mass with its prolonged history, along with a hemorrhagic FNA specimen exhibiting at lea st some cytologic features reminiscent of endocrine neoplasm, are among the factors that help in arriving at a suggestive diagnosis of paraganglioma, when other clinical features tend to sidetrack from interpretation of the c ytologic changes. 2) In the practice of FNA cytology if the possibility of paraganglioma arises, processing part of the specimen as a cell block with accompanying histology and immunohistochemistry can provide a definitive di agnosis of such lesion. (C) 2000 Wiley-Liss, Inc.